With few exceptions, most mineral-separation processes involve the use of substantial quantities of water and the final concentrate has to be separated from a pulp in which the water-solids ratio may be high. Dewatering, or solid-liquid separation, produces a relatively dry concentrate for shipment. Partial dewatering is also performed at various stages in the concentrator, so as to prepare the feed for subsequent processes. Sometimes tailings are also de-watered.

Dewatering methods can be broadly classified into three groups:

• Sedimentation (gravity and centrifugal)
• Filtration
• Drying